**Forecast models for Wellington, New Zealand, on September 2, 2026, indicate an overnight minimum near 11–13 °C, with trader probabilities clustering tightly around 10–12 °C because of small differences in how models handle radiative cooling under strong northwest winds.** Wellington’s spring conditions feature brisk NW flows that limit nocturnal temperature drops by mixing the boundary layer, while partly cloudy skies allow some long-wave radiation loss. Official guidance from sources such as the Met Office currently points to a nighttime low of about 13 °C, whereas other ensembles and statistical analogs suggest values closer to 11–12 °C; the resulting spread keeps implied probabilities for 10 °C, 11 °C, and 12 °C nearly equal. Stronger-than-average winds or a modest increase in cloud cover could push the minimum a degree higher, whereas clearer skies and lighter winds would favor the lower end of the range. With resolution only hours away, any late-model run or observational update from New Zealand forecasters could quickly shift the tight market equilibrium.